Load Balancing OKI DICOM-Embedded Printers. Deployment Guide v Copyright Loadbalancer.org

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1 Load Balancing OKI DICOM-Embedded Printers Deployment Guide v1.0.1 Copyright Loadbalancer.org

2 Table of Contents 1. About this Guide Loadbalancer.org Appliances Supported Loadbalancer.org Software Versions Supported OKI DICOM-Embedded Printer Software Versions Supported OKI DICOM-Embedded Printer Load Balancing OKI DICOM-Embedded Printers...4 Persistence (aka Server Affinity)... 4 Port Requirements... 4 Health Checks Deployment Concept...5 Virtual Service (VIP) Requirements Load Balancer Deployment Methods...5 Layer 7 SNAT Mode... 5 Layer 4 SNAT Mode... 6 Our Recommendation Loadbalancer.org Appliance the Basics...8 Virtual Appliance Download & Deployment...8 Initial Network Configuration... 8 Accessing the Web User Interface (WebUI)...9 HA Clustered Pair Configuration Appliance Configuration for OKI DICOM-Embedded Printers Using Layer 7 SNAT Mode...11 Configuring the Virtual Service (VIP) Defining the Real Servers (RIPs) Finalizing the Configuration Appliance Configuration for OKI DICOM-Embedded Printers Using Layer 4 SNAT Mode...12 Configuring the Virtual Service (VIP) Defining the Real Servers (RIPs) Testing & Verification...14 Running a Test Print Test Print Failure Using System Overview Technical Support Further Documentation Conclusion Appendix...16 Clustered Pair Configuration Adding a Slave Unit...16 Company Contact Information... 19

3 About this Guide 1. About this Guide This guide details the steps required to configure a load balanced OKI DICOM-embedded printer environment utilizing Loadbalancer.org appliances. It covers the configuration of the load balancers and also any OKI DICOM-embedded printer configuration changes that are required to enable load balancing. For more information about initial appliance deployment, network configuration and using the Web User Interface (WebUI), please also refer to the relevant Administration Manual: v7 Administration Manual v8 Administration Manual 2. Loadbalancer.org Appliances Supported All our products can be used for load balancing OKI DICOM-embedded printers. The complete list of models is shown below: Discontinued Models Current Models * Enterprise R16 Enterprise VA R16 Enterprise VA Enterprise R320 Enterprise R20 Enterprise MAX Enterprise 10G Enterprise Ultra Enterprise VA R20 Enterprise VA MAX Enterprise AWS ** Enterprise AZURE ** * For full specifications of these models please refer to: ** Some features may not be supported, please check with Loadbalancer.org support 3. Loadbalancer.org Software Versions Supported V7.6.4 and later 4. OKI DICOM-Embedded Printer Software Versions Supported OKI DICOM-Embedded Printer version 4.01 and later Page 3

4 OKI DICOM-Embedded Printer 5. OKI DICOM-Embedded Printer OKI s range of DICOM-embedded printers allow for medical images to be printed directly from medical equipment. Printing directly from DICOM modalities eliminates the need to use conversion software or costly external hardware as part of the medical printing workflow. OKI s printers can also be used for dayto-day printing tasks. Having a highly available print service allows printing to continue even when some printers are out of service, for example for maintenance. The load balancer will select a printer that is still online and ready to accept jobs and will send traffic there. Having a load balanced printing service also helps in a high volume printing environment, where multiple printers can share the printing load and increase the total pages per minute printing capacity. Overall, having a highly available print service improves the experience for physicians, medical professionals, and patients. Loadbalancer.org appliances also support load balancing print servers, offering additional flexibility and possibilities for load balancing a full printing environment. 6. Load Balancing OKI DICOM-Embedded Printers It's highly recommended that you have a working OKI DICOM-embedded printer environment first before implementing the load balancer. PERSISTENCE (AKA SERVER AFFINITY) OKI DICOM-embedded printers do not require session affinity at the load balancing layer. PORT REQUIREMENTS One port needs to be load balanced: Port Protocols Use TCP/DICOM DICOM print service HEALTH CHECKS It is recommended to use the DICOM specific health check when load balancing DICOM printers. This can be found on the load balancer by setting Health Checks to External script and then setting Check Script to the DICOM-C-ECHO health check. Page 4

5 Deployment Concept 7. Deployment Concept VIPs = Virtual IP Addresses The load balancer can be deployed as a single unit, although Loadbalancer.org recommends a clustered pair for resilience & high availability. Please refer to section 1 in the appendix on page 16 for more details on configuring a clustered pair. VIRTUAL SERVICE (VIP) REQUIREMENTS One virtual service is needed in this deployment, which load balances the DICOM printer traffic. 8. Load Balancer Deployment Methods The load balancer can be deployed in 4 fundamental ways: Layer 4 DR mode, Layer 4 NAT mode, Layer 4 SNAT mode, and Layer 7 SNAT mode. For OKI DICOM-embedded printers, using layer 7 SNAT mode is recommended. It is also possible to use layer 4 SNAT mode. These modes are described below and are used for the configurations presented in this guide. For configuring using layer 7 SNAT mode please refer to the section starting on page 11, and for configuring using layer 4 SNAT mode please refer to the section starting on page 12. LAYER 7 SNAT MODE Layer 7 SNAT mode uses a proxy (HAProxy) at the application layer. Inbound requests are terminated on the load balancer, and HAProxy generates a new request to the chosen Real Server. As a result, Layer 7 is a slower technique than DR or NAT mode at Layer 4. Layer 7 is typically chosen when either enhanced options such as SSL termination, cookie based persistence, URL rewriting, header insertion/deletion etc. are required, or when the network topology prohibits the use of the layer 4 methods. Page 5

6 Load Balancer Deployment Methods This mode can be deployed in a one-arm or two-arm configuration and does not require any changes to the Real Servers. However, since the load balancer is acting as a full proxy it doesn't have the same raw throughput as the layer 4 methods. The load balancer proxies the application traffic to the servers so that the source of all traffic becomes the load balancer. SNAT mode is a full proxy and therefore load balanced Real Servers do not need to be changed in any way Because SNAT mode is a full proxy any server in the cluster can be on any accessible subnet including across the Internet or WAN SNAT mode is not transparent by default, i.e. the Real Servers will not see the source IP address of the client, they will see the load balancers own IP address by default, or any other local appliance IP address if preferred (e.g. the VIP address), this can be configured per layer 7 VIP. If required, the clients IP address can be passed through either by enabling TProxy on the load balancer, or for HTTP, using X-forwarded-For headers. Please refer to chapter 6 in the administration manual for more details SNAT mode can be deployed using either a 1-arm or 2-arm configuration You should not use the same RIP:PORT combination for layer 7 SNAT mode VIPs and layer 4 SNAT mode VIPs because the required firewall rules conflict. LAYER 4 SNAT MODE Layer 4 SNAT mode is a high performance solution, although not as fast as the other layer 4 modes. Page 6

7 Load Balancer Deployment Methods The load balancer translates all requests from the external Virtual Service to the internal Real Servers in the same way as NAT mode (please refer to the previous page for details). Layer 4 SNAT mode is not transparent, an iptables SNAT rule translates the source IP address to be the load balancer rather than the original client IP address. Layer 4 SNAT mode can be deployed using either a one-arm or two-arm configuration. For two-arm deployments, eth0 is normally used for the internal network and eth1 is used for the external network although this is not mandatory. If the Real Servers require Internet access, Autonat should be enabled using the WebUI option: Cluster Configuration > Layer 4 Advanced Configuration, the external interface should be selected. Port translation is not possible in layer 4 SNAT mode i.e. having a different RIP port than the VIP port. You should not use the same RIP:PORT combination for layer 7 SNAT mode VIPs and layer 4 SNAT mode VIPs because the required firewall rules conflict. OUR RECOMMENDATION Where possible, we recommend that layer 7 SNAT mode is used. This mode is simple to implement, and requires no changes to be made to any network architecture or servers. Ultimately, the final choice does depend on your specific requirements and infrastructure. Layer 4 SNAT mode can also be used as an alternative to layer 7 SNAT mode. Page 7

8 Loadbalancer.org Appliance the Basics 9. Loadbalancer.org Appliance the Basics VIRTUAL APPLIANCE DOWNLOAD & DEPLOYMENT A fully featured, fully supported 30 day trial is available if you are conducting a PoC (Proof of Concept) deployment. The VA is currently available for VMware, Virtual Box, Hyper-V, KVM and XEN and has been optimized for each Hypervisor. By default, the VA is allocated 1 CPU, 2GB of RAM and has an 8GB virtual disk. The Virtual Appliance can be downloaded here. The same download is used for the licensed product, the only difference is that a license key file (supplied by our sales team when the product is purchased) must be applied using the appliance's WebUI. Please refer to the Administration Manual and the ReadMe.txt text file included in the VA download for more detailed information on deploying the VA using various Hypervisors. INITIAL NETWORK CONFIGURATION The IP address, subnet mask, default gateway and DNS settings can be configured in several ways as detailed below: Method 1 - Using the Network Setup Wizard at the console After boot up, follow the instructions on the console to configure the IP address, subnet mask, default gateway and DNS settings. Method 2 - Using the WebUI Using a browser, connect to the WebUI on the default IP address/port: To set the IP address & subnet mask, use: Local Configuration > Network Interface Configuration To set the default gateway, use: Local Configuration > Routing To configure DNS settings, use: Local Configuration > Hostname & DNS Method 3 - Using Linux commands At the console, set the initial IP address using the following command: ip addr add <IP address>/<mask> dev eth0 At the console, set the initial default gateway using the following command: route add default gw <IP address> <interface> At the console, set the DNS server using the following command: echo nameserver <IP address> >> /etc/resolv.conf If method 3 is used, you must also configure these settings using the WebUI, otherwise the settings will be lost after a reboot. Page 8

9 Loadbalancer.org Appliance the Basics ACCESSING THE WEB USER INTERFACE (WEBUI) The WebUI can be accessed via HTTP at the following URL: * Note the port number 9080 The WebUI can be accessed via HTTPS at the following URL: * Note the port number 9443 (replace with the IP address of your load balancer if it's been changed from the default) Login using the following credentials: Username: loadbalancer Password: loadbalancer To change the password, use the WebUI menu option: Maintenance > Passwords. Once logged in, the WebUI will be displayed as shown on the following page: Page 9

10 Loadbalancer.org Appliance the Basics (shows v8.2.x) HA CLUSTERED PAIR CONFIGURATION Loadbalancer.org recommend that load balancer appliances are deployed in pairs for high availability. In this guide a single unit is deployed first, adding a secondary slave unit is covered in section 1 of the appendix on page 16. Page 10

11 Appliance Configuration for OKI DICOM-Embedded Printers Using Layer 7 SNAT Mode 10. Appliance Configuration for OKI DICOM- Embedded Printers Using Layer 7 SNAT Mode You should not use the same RIP:PORT combination for layer 7 SNAT mode VIPs and layer 4 SNAT mode VIPs because the required firewall rules conflict. In the context of load balancing OKI DICOM-embedded printers, one load balancing method should be chosen and stuck to. Mixing layer 7 and layer 4 SNAT modes is not advisable. CONFIGURING THE VIRTUAL SERVICE (VIP) 1. Using the web user interface, navigate to Cluster Configuration > Layer 7 Virtual Services and click on Add a new Virtual Service 2. Define the Label for the virtual service as required, e.g. DICOM-Print 3. Set the Virtual Service IP Address field to the required IP address, e.g Set the Ports field to Set the Layer 7 Protocol to TCP Mode 6. Click Update to create the virtual service 7. Click Modfiy next to the newly created VIP 8. Set Persistence Mode to None 9. From the Health Checks drop-down list select External script 10. From the Check Script drop-down list that appears, select DICOM-C-ECHO 11. Click Update to apply the changes DEFINING THE REAL SERVERS (RIPS) 1. Using the web user interface, navigate to Cluster Configuration > Layer 7 Real Servers and click on Add a new Real Server next to the newly created VIP 2. Define the Label for the real server as required, e.g. OKI-DICOM-Printer-1 3. Set the Real Server IP Address field to the required IP address, e.g Set the Real Server Port to Page 11

12 Appliance Configuration for OKI DICOM-Embedded Printers Using Layer 7 SNAT Mode 5. Click Update 6. Repeat these steps to add additional real servers as required FINALIZING THE CONFIGURATION To apply the new settings, HAProxy must be reloaded as follows: 1. Using the WebUI, navigate to: Maintenance > Restart Services and click Reload HAProxy 11. Appliance Configuration for OKI DICOM- Embedded Printers Using Layer 4 SNAT Mode You should not use the same RIP:PORT combination for layer 4 SNAT mode VIPs and layer 7 SNAT mode VIPs because the required firewall rules conflict. In the context of load balancing OKI DICOM-embedded printers, one load balancing method should be chosen and stuck to. Mixing layer 4 and layer 7 SNAT modes is not advisable. CONFIGURING THE VIRTUAL SERVICE (VIP) 1. Using the web user interface, navigate to Cluster Configuration > Layer 4 Virtual Services and click on Add a new Virtual Service 2. Define the Label for the virtual service as required, e.g. DICOM-Print 3. Set the Virtual Service IP Address field to the required IP address, e.g Set the Ports field to Set the Protocol set to TCP 6. Set the Forwarding Method set to SNAT 7. Click Update to create the virtual service Page 12

Appliance Configuration for OKI DICOM-Embedded Printers Using Layer 4 SNAT Mode 8. Click Modfiy next to the newly created VIP 9. Make sure that the Persistent checkbox is not checked 10.

Click Update to apply the changes DEFINING THE REAL SERVERS (RIPS) 1.

13 Appliance Configuration for OKI DICOM-Embedded Printers Using Layer 4 SNAT Mode 8. Click Modfiy next to the newly created VIP 9. Make sure that the Persistent checkbox is not checked 10. From the Health Checks Check Type drop-down list select External script 11. From the External script drop-down list that appears, select DICOM-C-ECHO 12. Click Update to apply the changes DEFINING THE REAL SERVERS (RIPS) 1. Using the web user interface, navigate to Cluster Configuration > Layer 4 Real Servers and click on Add a new Real Server next to the newly created VIP 2. Define the Label for the real server as required, e.g. OKI-DICOM-Printer-1 3. Set the Real Server IP Address field to the required IP address, e.g Set the Real Server Port to Click Update 6. Repeat these steps to add additional real servers as required Page 13

Testing & Verification 12. Testing & Verification RUNNING A TEST PRINT An easy way to test if a load balanced OKI DICOM-embedded printer service is working is to send a test print to the VIP address.

Confirm that the load balancer can route to the real servers, i.e. the printers.

14 Testing & Verification 12. Testing & Verification RUNNING A TEST PRINT An easy way to test if a load balanced OKI DICOM-embedded printer service is working is to send a test print to the VIP address. If the test print works as intended then the virtual service is working correctly. TEST PRINT FAILURE If the test print fails, the following error message may be displayed: Troubleshooting 1. Confirm that the load balancer can route to the real servers, i.e. the printers. An easy way to check this is to confirm that the real servers are showing as green and online on the System Overview page. If the servers are showing as red then the load balancer cannot communicate with them, which may indicate a networking issue 2. If the real servers are showing as online, the next thing to check is that the same RIP:PORT combination is not being used for a layer 7 SNAT mode VIP and a layer 4 SNAT mode VIP. The required firewall rules conflict in such a scenario USING SYSTEM OVERVIEW The System Overview can be viewed in the WebUI. It shows a graphical view of all VIPs & RIPs (i.e. the OKI DICOM-embedded printers) and shows the state/health of each server as well as the state of the cluster as a whole. The example below shows that all three OKI DICOM-embedded printers are healthy and available to accept connections. Page 14

15 Technical Support 13. Technical Support For more details about configuring the appliance and assistance with designing your deployment please don't hesitate to contact the support team using the following address: 14. Further Documentation The Administration Manual contains much more information about configuring and deploying the appliance. It's available here: Conclusion Loadbalancer.org appliances provide a very cost effective solution for highly available load balanced OKI DICOM-embedded printer environments. Page 15

16 Appendix 16. Appendix 1 CLUSTERED PAIR CONFIGURATION ADDING A SLAVE UNIT If you initially configured just the master unit and now need to add a slave - our recommended procedure, please refer to the relevant section below for more details: A number of settings are not replicated as part of the master/slave pairing process and therefore must be manually configured on the slave appliance. These are listed below: Hostname & DNS settings Network settings including IP addresses, bonding configuration and VLANs Routing configuration including default gateways and static routes Date & time settings Physical Advanced Configuration settings including Internet Proxy IP address & port, Firewall table size, SMTP relay and Syslog server SNMP settings Graphing settings Firewall Script & Firewall Lockdown Script settings Software updates Version 7: Please refer to Chapter 8 Appliance Clustering for HA in the v7 Administration Manual. Version 8: To add a slave node i.e. create a highly available clustered pair: Deploy a second appliance that will be the slave and configure initial network settings Using the WebUI, navigate to: Cluster Configuration > High-Availability Configuration Page 16

as shown below: Once complete, the following will be displayed: To finalize the configuration,

17 Appendix Specify the IP address and the loadbalancer users password (the default is 'loadbalancer') for the slave (peer) appliance as shown above Click Add new node The pairing process now commences as shown below: Once complete, the following will be displayed: To finalize the configuration, restart heartbeat and any other services as prompted in the blue message box at the top of the screen Page 17

18 Appendix Clicking the Restart Heartbeat button on the master appliance will also automatically restart heartbeat on the slave appliance. Please refer to chapter 9 Appliance Clustering for HA in the Administration Manual for more detailed information on configuring HA with 2 appliances. Page 18

19 Appendix 2 COMPANY CONTACT INFORMATION Website URL: North America (US) Loadbalancer.org, Inc Linden Hill Road, Suite 201 Wilmington, DE USA Tel: (sales): (support): sales@loadbalancer.org support@loadbalancer.org North America (Canada) Loadbalancer.org Appliances Ltd Richards Street Vancouver, BC V6B 2Z4 Canada Tel: (sales): (support): sales@loadbalancer.org support@loadbalancer.org Europe (UK) Loadbalancer.org Ltd. Compass House North Harbour Business Park Portsmouth, PO6 4PS UK Tel: (sales): (support): +44 (0) sales@loadbalancer.org support@loadbalancer.org Europe (Germany) Loadbalancer.org GmbH Tengstraße München Germany Tel: (sales): (support): +49 (0) vertrieb@loadbalancer.org support@loadbalancer.org Page 19

Load Balancing Microsoft OCS Deployment Guide v Copyright Loadbalancer.org

Load Balancing Microsoft OCS Deployment Guide v Copyright Loadbalancer.org Load Balancing Microsoft OCS 2007 Deployment Guide v1.5.2 Copyright Loadbalancer.org Table of Contents 1. About this Guide...3 2. Loadbalancer.org Appliances Supported...3 3. Loadbalancer.org Software